Short answers, pulled from the story.
The oldest known iconographic representation of a chordophone dates back 3,300 years to a Hittite stone carving. This image depicts a bard playing a stringed instrument and stands as the earliest visual evidence in human history.
Antonio Torres Jurado revolutionized the instrument between 1817 and 1892 by increasing body size and altering proportions. He invented the fan-braced pattern that remains essentially unchanged today while establishing standard dimensions still used by luthiers worldwide.
The five-course baroque guitar emerged in Spain during the middle of the 16th century with documentation appearing around 1554 and 1555. Literary sources credit Vicente Espinel with creating the five-course guitar around 1550 though his birth date makes this claim historically impossible according to some critics.
Standard classical guitars contain nineteen frets while electric models range between twenty-one and twenty-four frets. Classical guitars typically use nylon strings whereas flat-top guitars feature steel strings and significantly larger bodies than classical models.
George Beauchamp invented the first successful magnetic pickup for guitar in 1931 and incorporated it into the Ro-Pat-In Frying Pan lap steel instrument. This device converted string vibrations into electrical signals for amplification leading to solid-body electric guitars gaining popularity after World War II.